[ 1135.334212][T11421] Could not find device with ifindex 2000 in netnsfd 11
[ 1135.335343][T11421] Could not find netns with fd: 2000
[ 1135.336300][T11421] Cannot link a netdevsim to itself
[ 1135.337464][T11421] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).